1. Technical Field
The present disclosure relates to a device for protecting an integrated circuit against external attacks and, in particular, against attacks performed from the back side of the integrated circuit.
2. Description of the Related Art
It may be desirable to protect an integrated circuit against external attacks which aim, for example, at determining the integrated circuit structure and operation, at accessing confidential data stored in the integrated circuit, or again at disturbing the circuit operation. An example of attack comprises partially etching the insulating layers from the front surface of the integrated circuit to access metal tracks of the last metallization levels, and creating metal pads connected to these tracks to measure the signals which transit therethrough.
The integrated circuit may comprise a protection device which enables to detect that an attack is being carried out and which can then control the stopping of the integrated circuit, or the deleting of confidential data.
An example of a device of protection against attacks performed on the front side of the integrated circuit uses metal tracks of the last metallization levels of the integrated circuit, which cover the metal tracks transmitting “useful” signals. A detection device is capable of detecting a rupture of these tracks, which corresponds to an attack. However, this protection device is ineffective against attacks on the back side of the integrated circuit.